Toonstra, who has previously been linked with AZ Alkmaar and FC Twente, is contracted at ADO until 2013 but is not ruling out a Swansea move, and has voiced admiration for their free-flowing style of play.

He told NUSport: "If Swansea are (interested), then I would take that chance. It's a nice club and they play Dutch football."

ADO captain and central defender Kum is out of contract in the summer and has previously turned down a new deal at the club and an offer from NEC Nijmegen.

Swansea have previously dipped into the Dutch transfer market, with Michel Vorm and Kemy Agustien already on their books.